code: def test_jax_no_data_format(request: Any) -> None:
      backend = request.config.option.backend
      if backend != "jax":
          pytest.skip()
  
      class Model:
          def __call__(self, x: Any) -> Any:
              return x
  
      model = Model()
      bounds = (0, 1)
      fmodel = fbn.JAXModel(model, bounds, data_format=None)
      with pytest.raises(AttributeError):
          fmodel.data_format
  
file_path: foolbox/tests/test_models.py
imports: from typing import Tuple, Any
  import pytest
  import eagerpy
  import numpy
  import copy
  import foolbox
label_desc: Use image node_id 6 for calling a global function with example usage: test_jax_no_data_format(request) and returns: x